Add support for YAML file reader Config Manager

[niveathika]

Description:
Siddhi now only supports the InMemory config manager to set system properties. However, initialising the in-memory config manager is vastly different from the siddhi-runner-distribution method of reading from the conf file in (RUNNER_HOME)/conf/runner/deployment.yaml file.

This issue is to track a new feature, YAMLConfigManger, which can be initiated with a file path of a YAML file, which can be used to configure the Siddhi system properties.

Sample of the YAML file will be as follows,

# Siddhi related properties
properties:
  partitionById: TRUE
  shardId: shard1

# Siddhi references
refs:
  - ref:
      name: source1
      type: source-type
      properties:
        property1: value1
        property2: value2

# Siddi Extensions system Parameters
extensions:
  - extension:
      name: rdbms
      namespace: store
      properties:
        mysql.batchEnable: true
        mysql.batchSize: 1000
        mysql.indexCreateQuery: "CREATE INDEX {{TABLE_NAME}}_INDEX ON {{TABLE_NAME}} ({{INDEX_COLUMNS}})"
        mysql.recordDeleteQuery: "DELETE FROM {{TABLE_NAME}} {{CONDITION}}"
        mysql.recordExistsQuery: "SELECT 1 FROM {{TABLE_NAME}} {{CONDITION}} LIMIT 1"